feat: enhance E2E testing setup and model reporting

- Added a new fixture to manage runtime report artifacts in a writable temp directory during E2E tests, addressing permission issues in local CI/dev environments.
- Updated `conftest.py` to include a requirements.txt file in the model packaging path for training activities.
- Refactored existing fixtures to use `pytest.fixture` instead of `pytest_asyncio.fixture` for better compatibility.
- Enhanced the `Reports` class to include a target alias for report metrics, ensuring compatibility with Evidently's reporting requirements.
- Introduced new test scenarios to validate the handling of missing and whitespace-only `date_column` inputs in the training workflow.

These changes improve the robustness of the E2E testing framework and enhance the clarity of model reporting metrics.

model_manager/utils/repository/data_manager_repository.py

@@ -565,6 +565,13 @@ class DataManagerRepository(SientiaMonitoring):
         current_data = y_val_pred[['prediction']].join(data.val_data, how='inner')
         current_data_float = current_data.astype(np.float64)
 
+        # Evidently's ConflictTargetMetric expects a literal `target` column name.
+        # Keep the original target column and provide this alias for report metrics.
+        target_col = data.params.target_variable
+
+        reference_data_float['target'] = reference_data_float[target_col]
+        current_data_float['target'] = current_data_float[target_col]
+
         # Initialize report generator
         base_path = self._get_reports_directory()
         data.run_dir = self._create_run_directory(base_path, data.run_name)
@@ -581,7 +588,6 @@ class DataManagerRepository(SientiaMonitoring):
         )
 
         # Generate report sections
-        target_col = data.params.target_variable
         feature_and_target_cols = data.params.variable_columns + [target_col]
         report.add_data_quality_section(columns=feature_and_target_cols)
         report.add_data_drift_section(columns=feature_and_target_cols)